Bug in shared formulas: non-fixed cells are not updated if the formula has a fixed cell (#2354)

Example: right shift shared formula: IF(A$1=0,0,A1/A$1)
Expected value: IF(B$1=0,0,B1/B$1)
Actual value: IF(B$1=0,0,A1/B$1)

Similar behavior is observed when copying formulas vertically.
This issue occurs because a fixed and a non-fixed cell hit the same element of the $newCellTokens array by index $cellIndex

src/PhpSpreadsheet/ReferenceHelper.php

@@ -717,10 +717,12 @@ class ReferenceHelper
                                 $toString = ($match[2] > '') ? $match[2] . '!' : '';
                                 $toString .= $modified3;
                                 [$column, $row] = Coordinate::coordinateFromString($match[3]);
+                                $columnAdditionalIndex = $column[0] === '$' ? 1 : 0;
+                                $rowAdditionalIndex = $row[0] === '$' ? 1 : 0;
                                 //    Max worksheet size is 1,048,576 rows by 16,384 columns in Excel 2007, so our adjustments need to be at least one digit more
                                 $column = Coordinate::columnIndexFromString(trim($column, '$')) + 100000;
                                 $row = (int) trim($row, '$') + 10000000;
-                                $cellIndex = $row . $column;
+                                $cellIndex = $row . $rowAdditionalIndex . $column . $columnAdditionalIndex;
 
                                 $newCellTokens[$cellIndex] = preg_quote($toString, '/');
                                 $cellTokens[$cellIndex] = '/(?<![A-Z\$\!])' . preg_quote($fromString, '/') . '(?!\d)/i';

tests/data/ReferenceHelperFormulaUpdates.php

@@ -1,6 +1,20 @@
 <?php
 
 return [
+    [
+        '=IF(A$1=0,0,A1/A$1)',
+        1,
+        0,
+        '2021',
+        '=IF(B$1=0,0,B1/B$1)',
+    ],
+    [
+        '=IF($A1=0,0,A1/$A1)',
+        0,
+        1,
+        '2021',
+        '=IF($A2=0,0,A2/$A2)',
+    ],
     [
         '=SUM(C3:E5)',
         -2,